Updated ConcatOptimization to support Concat with 0D input of one dimension (#2012)

Updated ConcatOptimization to support Concat with 0D input of one dimension (#2012)

* Updated ConcatOptimization transformation to work when one dimension of input to Concat is 0D

* Fixed ConcatOptimization transformation to reconnect input edges to Concat

* Completely re-written ConcatOptimization

* Updated Concat0D optimization transformation

* Fixed order of traversing Concat input ports

* Refactored ConcatOptimization transformation to use `delete_input_port` function

* Detele trailing unconnected ports in the ConcatOptimization.py

* Cleaner implementation of ConcatOptimization + unit test